The ML-RMB500 battery is fully compatible with all Roomba 500, 600, and 700 series. Mighty Max ML-RMB500 Brand new Battery Pack which is compatible with iRobot Roomba Advanced Power System APS Battery. ML-RMB500 replaces the original iRobot Roomba 80501 battery. ML-RMB500 is an Ni-Cd Rechargeable battery that keeps Roomba running at peak performance, cleaning up your room in a single charge. ML-RMB500 can be charged or discharged as needed without loss of capacity. Easy to charge and connect APS battery compatible with all Roomba FloorVac models. Replacement battery for iRobot Roomba 500 600 700 series vacuum cleaner. 14.4V 2.0AH NiCD battery. Mighty maximum batteries are made with the highest quality materials.